Engineer's compartment

Allen J. Schaben / Los Angeles Times

Regular riders on the route said the Metrolink train often stops at a junction to wait for an Union Pacific freight train headed toward downtown Los Angeles to switch to the siding. On Friday, however, the Metrolink train proceeded before the freight train had passed, tripping an alarm at the commuter lines dispatch center.

Regular riders on the route said the Metrolink train often stops at a junction to wait for an Union Pacific freight train headed toward downtown Los Angeles to switch to the siding. On Friday, however, the Metrolink train proceeded before the freight train had passed, tripping an alarm at the commuter lines dispatch center. (Allen J. Schaben / Los Angeles Times)

Regular riders on the route said the Metrolink train often stops at a junction to wait for an Union Pacific freight train headed toward downtown Los Angeles to switch to the siding. On Friday, however, the Metrolink train proceeded before the freight train had passed, tripping an alarm at the commuter lines dispatch center.